We use a copy of dokuwiki, with a page for each used subnet. Whenever anything is commissioned, it's updated, althought we're small enough that if it's not updated for something, we can probably work out who did it.
You can't rely on UDP to deliver packets in order because the specification doesn't provide those guarantees. Even assuming the most ideal situation, a single piece of ethernet cable between two hosts, there is still the matter of the OS, the network stack, the NIC driver, and the libc implementation that your writing against.
At every step in that chain, the writers of that code will have chosen NOT to prioritise ordering UDP packets even if they arrive in order for the simple reason that they don't have to.
One contrived example could be the data structure that incoming packets are read into, which might be a ring buffer. Packets arriving in order, will be placed, in order into the ring buffer, but it may be simpler for the driver writer to dump them to the upper layers of the networking code in memory order, hence randomising their ordering.
Taking your situation, a virtual machine run on a shared infrastructure that will be run for volume, not performance, then the probability of predicting the order UDP packets will be received will be low.
In short, if the spec says you can't rely on UDP packet ordering. You can't rely on it, and you can't try to tweak the environment to give a stronger guarantee than the spec ever promised.
Best Answer
You want to use Category 6 or 6a (aka "Class Ea"), as this will allow use of 10 GigE over copper if you ever need it:
http://en.wikipedia.org/wiki/10_Gigabit_Ethernet#10GBASE-T
Cat6 allows for 37-55m (121-180 ft) cable runs (depending on how much electrical noise there is in the environment) for 10 GigE; Cat6A allows for 100m (330 ft) runs at 10 GigE. Either will be fine for 1 GigE. If your runs are with-in the shorter lengths, then Cat6 should be sufficient. Don't think UTP or STP would make much of a difference.
I'd get quotes for 'parts and labor' for each type of cabling and see what the cost differences are: it's usually easier to "future proof" things at the beginning than retrofitting things down the road.
If you're doing any fibre you may also want to look at the costs for both OM3 and OM4 (which was just released and will help with future 40 and 100 GigE support in your DC).